Hi Tara,

In the very distant future (~5 billion years) our Sun will go through a stage in which it swells (called a red giant stage) to a size that will engulf the planets closest to it, including Mercury, Venus, and possibly the Earth. This is a process that occurs as the Sun burns through all of its energy and starts to "die", or become a white dwarf (white dwarfs can be thought of as "retired" stars). However, we do not have to worry about this since it won't occur for billions of years!

Holly